I never really thought of the word obconic as being a useful adjective. Or that it could be used as an ironical descriptive. Perhaps I'm the last to know that as a word it is synonymous with "pearshaped" which could describe how some of my posts turn out - set out with the best intentions, before going "pearshaped."
I don't suppose this piece of information will helpfully enrich anyone's vocabulary or enliven their ability to be elegantly varied. Anymore so than the knowledge that "rostrate" describes something which is boat shaped ( what else is boat shaped other than a boat?) "scaphoid" is bow shaped ( rather than some ghastly disease hybrid involving scabies and typhoid); falcate could describe (perhaps only from the pen of the late Anthony Burgess) something which is sickle shaped - I shouldn't think everyone knows what sickle shaped means these days, hammer and sickle flags no longer having any real relevance. And "ligulate" which could stand in for, if one wishes to be purposefully obscure, tongue shaped. Ligulate and groove, hmmm doesn't seem to have quite the same ring to it - which could bring me to an alternative bell shaped word. But the link will have to do the work for that one.